1. Field of Invention
This invention relates generally to electrical interconnection systems and more specifically to improved power connectors.
2. Discussion of Related Art
Electrical connectors are used in many electronic systems. It is generally easier and more cost effective to manufacture a system on several printed circuit boards (PCBs) that are connected to one another by electrical connectors than to manufacture a system as a single assembly. A traditional arrangement for interconnecting several PCBs is to have one PCB serve as a backplane. Other PCBs, which are called daughter boards or daughter cards, are then connected through the backplane by electrical connectors in an electrical interconnection system.
Some of the electrical connectors are designed to carry high speed data signals between the PCBs. They are referred to as signal connectors, and they typically have conductive elements that are shaped to provide a desired impedance or other properties to allow data signals to be transmitted with high integrity. Some other electrical connectors, called power connectors, are designed to carry larger amounts of current, and can be used to couple a supply of power from a subassembly connected to the backplane to the daughter cards also connected to the backplane. Typically, a power connector is configured with a supply path and a return path, forming a closed circuit that allows a flow of current. Unlike signal connectors, power connectors have conductive elements adapted to carry large amounts of current, such as 10 amperes or more.
In recent years, electronic systems have generally become smaller, faster and functionally more complex. These changes mean that the number of circuits in a given area of an electronic system, along with the frequencies at which the circuits operate, has increased significantly. Modern systems pass more data between PCBs and require electrical connectors that are electrically capable of handling more data at higher speeds than connectors of even a few years ago.
One of the difficulties in making a high density, high speed connector is that electrical conductors in the connector can be so close together that there can be electrical interference between adjacent signal conductors. Accordingly, a focus for improving signal integrity in an interconnection system has been to reduce interference between signal conductors that carry high speed data signals.
Various approaches have been used for this purpose, including incorporating shielding between the signal conductors, changing the shape or position of the signal conductors relative to ground conductors and incorporating magnetically or electrically lossy or absorptive material into the connector.